我正在通过sudo npm install ionic -g安装ionic

并得到以下错误

>     /root/.nvm/versions/node/v4.2.2/bin/ionic ->
> /root/.nvm/versions/node/v4.2.2/lib/node_modules/ionic/bin/ionic
>  
>     > node-sass@3.4.2 install
> /root/.nvm/versions/node/v4.2.2/lib/node_modules/ionic/node_modules/node-
> sass
>     > node scripts/install.js
>  
>  
>     module.js:340
>         throw err;
>               ^
>     Error: Cannot find module
> '/root/.nvm/versions/node/v4.2.2/lib/node_modules/ionic/node_modules/node-
> sass/scripts/install.js'
>         at Function.Module._resolveFilename (module.js:338:15)
>         at Function.Module._load (module.js:280:25)
>         at Function.Module.runMain (module.js:497:10)
>         at startup (node.js:119:16)
>         at node.js:902:3
>     npm ERR! Linux 3.13.0-32-generic
>     npm ERR! argv "/root/.nvm/versions/node/v4.2.2/bin/node"
> "/root/.nvm/versions/node/v4.2.2/bin/npm" "install" "ionic" "-g"
>     npm ERR! node v4.2.2
>     npm ERR! npm  v2.14.7
>     npm ERR! code ELIFECYCLE
>  
>     npm ERR! node-sass@3.4.2 install: `node scripts/install.js`
>     npm ERR! Exit status 8
>     npm ERR!
>     npm ERR! Failed at the node-sass@3.4.2 install script 'node
> scripts/install.js'.
>     npm ERR! This is most likely a problem with the node-sass package,
>     npm ERR! not with npm itself.
>     npm ERR! Tell the author that this fails on your system:
>     npm ERR!     node scripts/install.js
>     npm ERR! You can get their info via:
>     npm ERR!     npm owner ls node-sass
>     npm ERR! There is likely additional logging output above.
>  
>     npm ERR! Please include the following file with any support request:
>     npm ERR!     /root/npm-debug.log

离子论坛中也列出了该问题：-https: //forum.ionicframework.com/t/installing-ionic-not-
successful-solved/36050/7

我曾尝试多次更改节点，npm，cordova版本，但是每次遇到此错误时，我都认为这与版本无关。在某些地方，有人提到从根目录安装离子可能会有所帮助，所以我也这样做了。

请帮助我找出这一点。谢谢